We, at Department of Orthopedic Surgery, College of Medicine, Pusan National University, applied epiphyseal distraction as a method of limb lengthening, using unilateral one-plane pin fixator(ORTHOFIX) and bilateral multi-plane ring fixator(SEQUOIA) to three children with limb length discrepancies and angulation deformity due to injury of epiphyseal plate, and obtained following results. l. At first case, on whose distal femoral physis, bone bridge occupied about 20% of total epiphyseal plate and distributed mainly on the lateral side. At 10 days of distraction, epiphysiolysis occurred from the lateral side at first and angulation deformity was corrected. Epiphysiolysis on the medial side of physis appeared apparently after 60mm distraction. Bone lengthening of 4.2cm and correction of 25 valgus deformity were achieved after 72mm distraction for about 10 weeks. The percentage of increase in the initial length achieved was 11.67% and healing index was 27.86. 7 months later, loss of lengthening of 2.7cm was observed and it was considered that this was due to relatively short corticalization phase. 2. At second case, on whose distal tibial physis, bone bridge occupied about 40% of total epiphyseal plate and distributed on the medial side. At 10 days of distraction, epiphysiolysis occurred on the medial side of the epiphyseal plate, but not on the lateral side and instead of further lengthening, valgus deformity of the ankle appeared. It was thought that asymmetric distraction was attributed to the difference between the force applied on the medial side and that applied on the lateral side of the epiphyseal plate by unilateral one-plane pin fixation. 3. At third case, on whose distal tibial physis, bone bridge occupied about 75% of total epiphyseal plate. No epiphysiolysis occurred. there was a difficulty in observation of epiphysiolysis because ring fixator was overlapped with the epiphyseal plate on radiographs.